#include<stdio.h>
#include<vector>
using namespace std;
int nr, niv,euler[100004<<1],nivel[100004<<1],f[100004<<1],lg[100004<<1];
vector<int> v[100004];
int dfs(int k)
{

    for(int i=0;i<v[k].size();i++)
    {

        nr++;
        niv++;
        euler[nr]=v[k][i];
        if(f[v[k][i]]==0)
            f[v[k][i]]=nr;
        nivel[nr]=niv;
        dfs(v[k][i]);
        niv--;

        nr++;
        euler[nr]=k;
        nivel[nr]=niv;

    }
}
int rmq[100004<<1][20],sol[100004<<1][20];
int n,m,x;
int main()
{
    int i;
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(i=1;i<=n-1;i++)
    {

        scanf("%d",&x);
        v[x].push_back(i+1);
    }
    nr=1;
    nivel[1]=0;
    euler[1]=1;
    dfs(1);
    nivel[nr]=0;
    for(i=2;i<=nr;i++)
        lg[i]=lg[i/2]+1;

    for(i=1;i<=nr;i++)
    {

        rmq[0][i]=nivel[i];
        sol[0][i]=euler[i];
    }
    for(i=1;(1<<i)<=nr;i++)
    {

        for(int j=1;j<=nr-(1<<i)+1;j++)
        {
            int l=1<<(i-1);
            if(rmq[i-1][j]>rmq[i-1][j+l])
            {
                rmq[i][j]=rmq[i-1][j+l];
                sol[i][j]=sol[i-1][j+l];

            }
            else
            {
                rmq[i][j]=rmq[i-1][j];
                sol[i][j]=sol[i-1][j];
            }

        }

    }
    int y;
 /*   for(i=1;i<=n;i++)
        printf("%d ",f[i]);
    printf("\n");*/
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        x=f[x];
        y=f[y];
        int diff=y-x+1;
        int l=lg[diff];
        int sh=diff-(1<<l);
        if(rmq[l][x]>rmq[l][x+sh])
        {

            printf("%d\n",sol[l][x+sh]);
        }
        else printf("%d\n",sol[l][x]);

    }

    return 0;
}